From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (from majordomo@localhost) by pauillac.inria.fr (8.7.6/8.7.3) id WAA00711; Wed, 9 Jun 2004 22:03:07 +0200 (MET DST) X-Authentication-Warning: pauillac.inria.fr: majordomo set sender to owner-caml-list@pauillac.inria.fr using -f Received: from nez-perce.inria.fr (nez-perce.inria.fr [192.93.2.78]) by pauillac.inria.fr (8.7.6/8.7.3) with ESMTP id WAA00893 for ; Wed, 9 Jun 2004 22:03:06 +0200 (MET DST) Received: from biscayne-one-station.mit.edu (BISCAYNE-ONE-STATION.MIT.EDU [18.7.7.80]) by nez-perce.inria.fr (8.12.10/8.12.10) with ESMTP id i59K35EV017525 for ; Wed, 9 Jun 2004 22:03:05 +0200 Received: from manawatu-mail-centre.mit.edu (MANAWATU-MAIL-CENTRE.MIT.EDU [18.7.7.71]) by biscayne-one-station.mit.edu (8.12.4/8.9.2) with ESMTP id i59K346G000195 for ; Wed, 9 Jun 2004 16:03:04 -0400 (EDT) Received: from psi-phi.mit.edu (PSI-PHI.MIT.EDU [18.187.1.35]) (authenticated bits=56) (User authenticated as jfc@ATHENA.MIT.EDU) by manawatu-mail-centre.mit.edu (8.12.4/8.12.4) with ESMTP id i59K34oL016296 for ; Wed, 9 Jun 2004 16:03:04 -0400 (EDT) Received: (from jfc@localhost) by psi-phi.mit.edu (8.12.9) id i59K33q8024571; Wed, 9 Jun 2004 16:03:03 -0400 Message-Id: <200406092003.i59K33q8024571@psi-phi.mit.edu> To: caml-list@inria.fr Subject: Re: [Caml-list] 32 bit floats, SSE instructions In-Reply-To: Your message of "Wed, 09 Jun 2004 11:52:23 PDT." <20040609185223.GA4330@tallman.kefka.frap.net> Date: Wed, 09 Jun 2004 16:03:03 -0400 From: John Carr X-Miltered: at nez-perce with ID 40C76CF9.000 by Joe's j-chkmail (http://j-chkmail.ensmp.fr)! X-Loop: caml-list@inria.fr X-Spam: no; 0.00; caml-list:01 floats:01 jfc:01 floats:01 scalars:01 scalar:01 medium-size:99 bigarray:01 arithmetic:01 float:02 float:02 allocated:03 data:03 vector:04 array:04 Sender: owner-caml-list@pauillac.inria.fr Precedence: bulk > I'll add my vote; I find Xavier's occasional comments to be the > highlight of the mailing list. I think it's clear where he was headed: a general purpose 32 bit float type with 32 bit floating point arithmetic is not sufficiently useful to justify the implementation effort. As a general rule, on modern processors operations on 32 bit floats are not faster than operations on 64 bit floats. 32 bit float scalars do not save much space. 32 bit floats would be useful for three reasons: 1. If vector operations could be done on 32 but not 64 bit quantities. Scalar is about the same speed. SSE could be helpful but I think you would need significant work in the code generator. 2. To save space in large data structures. Bigarray is already available for this purpose. 3. To save space when many medium-size structures are allocated. A float32 record/array type would be helpful. ------------------- To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ Beginner's list: http://groups.yahoo.com/group/ocaml_beginners